The manufacture of semiconductor and other electronic devices including wafers, die, substrates, chips, and the like, includes steps such as sawing, scribing, breaking, sorting, inspecting, bonding, shipping, storage and additional processing. A number of apparatus and methods are commonly employed by processors of such devices in the handling thereof. One such method involves the use of carriers, or trays, which are formed with a plurality of cavities in the face thereof in which the chips are loaded. Typical disadvantages in the use of cavity trays include:
(a) Many different cavity sizes are needed to accommodate the multitude of chip sizes that are available.
(b) Unless the chip size and cavity size are very closely matched, the chip can rotate within the cavity and make subsequent automatic pickup systems, which require precise chip locations, more difficult.
(c) Chips may turn over within the cavities during shipment, and thus require re-orientation prior to subsequent processing.
(d) Chips may break as they move within the cavities during shipment.
(e) Chips tend to be difficult to place within a cavity, particularly small chips, by automatic equipment, since the ships tends to bounce out.
(f) Chips, particulary small chips, tend to easily dislodge and fly out of the tray, unless particular care is exercised, when the cavity tray is opened.
Other methods for holding and handling chips include:
(a) A film that contains a pressure sensitive adhesive mounted in a frame. Such frames are often difficult to handle and require special equipment to remove chips from the adhesive film. Commonly, this includes a probe from the bottom of the film to push the chip from the adhesive, and a vacuum tool from the top to capture and remove the chip. The probe sometimes causes the chip to be damaged.
(b) A non-adhesive elastomeric film that holds chips in place because of intimate surface contact between film and chip. Such films are ordinarily mounted on rigid substrates. Predominantly, small chips are handled on this type of system since larger ones, with increased surface contact area, are difficult to remove by ordinary vacuum techniques.
(c) A system similar to (b) where the surface of the elastomer has been texturized to reduce the surface contact between chips and elastomer, and thus allow for the easier removal of both larger and smaller chips. This system is disclosed in U.S. Pat. No. 4,395,451 issued July 26, 1984 entitled Semiconductor Wafer and Die Handling Method and Means, by the present inventor. While this sytem has a number of advantages, it is sometimes difficult to control the degree of texturization so that sufficient surface contact is maintained to retain chips in place.
(d) A system which includes a base member having a substantially flat upper face formed with recess means therein, together with a thin flexible film supported thereon upon which semiconductor chips, or the like, are supported. To facilitate removal of chips from the film the film is drawn downwardly into the recess means by reducing the gas pressure is the recess means thereby reducing the surface contact between the chip and film which, in turn, reduces the force by which the chip is attached to the film. For use with small objects, formation of suitable recess means in the base member is difficult, and may require costly tooling. Such a system is shown in copending U.S. patent application Ser. No. 497,430 filed May 24, 1983 entitled Method and Means for Handling Semiconductor and Similar Electronic Devices, which invention is assigned to the assignee of the present invention.